Fix cluster integration HTTP adapter

What does this MR do and why?

Somehow, !76879 (merged) caused typhoeus to become the default adapter for all elasticsearch clients, causing problems for the cluster integration, which apparently has Net::HTTP specific needs.

See #350519 (closed)

How to set up and validate locally

  1. Add a certificate-based cluster to your GDK
  2. Install Elasticstack in the cluster and enable the Elasticstack integration
  3. In the rails console, run
    cluster = Clusters::Cluster.last; client = cluster&.elasticsearch_client;

This should succeed with some search results. Without the fix, we get

ETHON: Libcurl initialized
ETHON: performed EASY effective_url=https://gdk.test:60048/api/v1/namespaces/gitlab-managed-apps/services/elastic-stack-elasticsearch-master:9200/proxy/_search response_code=0 return_code=bad_content_encoding total_time=0.031262
Faraday::ConnectionFailed: SSL peer certificate or SSH remote key was not OK
from /Users/hfyngvason/.asdf/installs/ruby/2.7.5/lib/ruby/gems/2.7.0/gems/typhoeus-1.4.0/lib/typhoeus/adapters/faraday.rb:106:in `block in request'

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.